Hydraulic power system



June 3, 1941. E. A. ROCKWELL HYDRAULIC POWER SYSTEM Filed Nov. 25, 1938 5 Sheets-Sheet 1 INVENTOR ldflw ATTOR Y June 1941- E. A. ROCKWELL 2,244,317

HYDRAULIC POWER SYSTEM Filed Nov. 25, 1958 5 Sheets-Sheet 2 m] H I l 7 26 6 4 i M y W %/J% 7 Z1 Z6 6 20 I *4 .1 Z?

\ 0 I V 1 v WWW llullllllllnllllli'r'iill III ATTORN Y June 3, 1941. E. A. ROCKWELL HYDRAULIC POWER SYSTEM 5 sheets-sheet s Filed Nov. 25, 1958 INVENTOR ATTO RNEY June 3, 1941. E. A. ROCKWELL HYDRAULIC POWER SYSTEM Filed Nov. 25, 1958 S-Sheets-Sheet 4 R Q B a Q Q h m. 2 E @r .mm mm Nb Q INVENTOR BY 4mm ATTO EY June 3, 1941. E. A. ROCKWELL 2,244,317

HYDRAULIC POWER SYSTEM Filed Nov. 25, 1938 5 Sheets-Sheet 5 INVENTOR g gg -fimw M Patented June 3, 1941 UNITED STATES PATENT OFFICE HYDRAULIC rowan srsram Edward A. Rockwell, Forest 111118, N. Y. Application November 25,1938, Serial No. 242,255

28 Claims. (Cl. '188-852) My invention relates particularly to a system adapted to apply hydraulic power to the operation of apparatus of any desired character but which is especially applicable for the control of automobile accessories.

The object of my invention is to provide a hydraulic system acting as a relay or for applying reverse modulation in the control of apparatus wherever desired, but which is applicable especiall for the control of automobile accessories. One of theobjects of my invention is to provide a relay valve in connection therewith, and another object is to provide means whereby reverse modulation is obtained, that is to say a modulating pressure which is so arranged that the higher the hydraulic pressure applied a smaller degree of actuation of the accessory is obtained and vice versa. This is particularly adaptable, for example, in connection with means as set forth hereinafter, for providing a safety feature, as, for instance, on brakes in which the brakesare normally pressed into action in case of any failure of the hydraulic system, which latter is utilized for throwing the brakes out of action as the hydraulic pressure applied thereto increases. The latter provides an effective automatlc safety feature in the hydraulic system, as applied to various automotive accessories.

While my invention is capable of embodiment in many different forms, by way of illustration I have shown only certain embodiments thereof in the accompanying drawings, in which- Fig. 1 is a diagrammatic elevation of a hydraulic system made in accordance with my invention:

Fig. 2 is a side elevation showing the main hydraulic actuating unit;

Fig. 3 is a vertical section through the same;

Fig. 4 is a longitudinal horizontal section through the booster used therein;

Fig. 5 is a longitudinal vertical section through the relayvalve structure therein;

Fig. 6 is a plan view of the same;

Fig. '7 is a horizontal longitudinal section of the automatic pack device contained therein;

Fig. 8 is a longitudinal section of a modified form of the relay valve structure which can be used instead of the relay valve shown in Fig. 5;

Fig. 9 is a perspective view of the tubular valve therein; and

Fig. 10 is a cross-section of a hydraulic mechanical operating unit.

In the form of my invention as shown in the accompanying drawings, '1 have illustrated a frame I of an automobile chassis, comprising two longitudinal U-beams 2 and 2 and a transverse U-beam I. Mounted on the .chassis of the automobile, at any desired point accessible to the.

driver, there is provided a foot-pedal lever 5 carried by a pivot 6 having a valve operating rod 1 pivotally connected to said lever and which, at the other end, is screw-threaded into a valve .operating yoke 8, locking screws 9 being provided to secure the rod 1 and yoke 8 together, which is pivotally mounted on a rear link I0 and a front valve operating link and lever II which are pivotally carried in a bifurcated bracket i2 which in turn is screw-threaded at its rear end to a brake-operating-rod l3, a locking nut It being provided to tighten the bracket l2 on the brake-rod ii. -The link I. and lever it provide for longitudinal parallel movement of the yoke 8 when operated by the foot-pedal lever 5. The bracket I2 is, furthermore, secured by bolts l5 and ii to a valve housing il. At its forward end the valve housing H has screw-threaded into the same a cap it provided with a central opening I! to receive a plunger 20 which abuts against the end of the lever II. A rubberboot 2i, to prevent the access of dirt, is received at one end in a recess 22 in the cap l8 and at the other end in a recess 23 in the plunger 20. An annular rubber seal 24, such as is shown in Fig. 8, U-shaped in cross section, is also can-ied in the cap I! around the plunger 20 to prevent the leakage of low pressure hydraulic fluid from the valve structure. At its rear end the plunger 20 is received in a slidable head 25 carried within a four-piecev cylindrical shell 26 having composite parts 26a, 26b, 26c, 26d, separated by rubber seals 26e, 261, 269, within the valve housing I], the

composite cylindrical shell 26 having, also, terminal rubber seals 26h, 26f. The slidable head 25 is normally urged in a forward direction by means of a spring 21 which abuts against the a same, and after passing through the valve struc- .flattened valve seat 32 adapted to contact, when closed, with the slidable head 25. The edge of this end of the tubular valve 2| is provided with a chambered portion 33 so that, as a result, the flattened valve seat will have a diameter which is somewhat less than the diameter of the rear portion of the tubular valve 3| to prevent the hydraulic pressure from pushing the slidable need 25 off said valve seat. However, this diameter of the flattened valve seat 32 is not made much smaller than the diameter of the rear end of the tubular valve 3|, so as thus to avoid requiring the head 25, and therefore, the footpedal 5, to change the foot pressure too much in the decreasing or oil modulation control.

The valve housing l1 has a high pressure inlet 34 for hydraulic liquid under any desired pressure, which may be, for example, 500 to 1000 lbs. per square inch, and is provided with a low pressure hydraulic liquid outlet 35 and a modulating pressure port 38 for modulated pressure to be supplied for operating the brake or other automobile accessory. The high pressure hydraulic liquid, after entering the'port 34, is received in an annular passageway 31 in the exterior of the cylindrical shell 28c and which is connected by a port 38 to an internal annular passageway 38 which extends to the front end of the shell 280 so as to end in an annular valve seat 48 on the rear of the end of the shell 25b, the edge of the said valve seat 48 being slightly smaller in diameter than the diameter of the rear end of the tubular valve 3| so as to insure a positive closing of the tubular valve 8| against said valve seat. On the exterior of the tubular valve 3| there is a tapered valve surface 4| cooperating with said valve seat 48 to thus provide a valve which is normally closed to prevent the entry of the high pressure liquid. When, by the movement of the pedal lever 5, the sliding head 25 is moved to the rear to close the valve against the valve seat 32 and thereafter unseat the valve 4| from the seat 48, the high pressure fluid will then have access through an annular passageway 42 and ports 43 to a longitudinal passageway 44 in the interior of the tubular valve so that the high pressure liquid can then have access to the rear end of the tubular valve 3| and thence to an internal annular passageway 45, radial ports 48 and an external annular passageway 41 in the shell 28d to the modulating pressure port 38. The modulating pressure thus applied through the port 38 passes by means of a flexible rubber tube 48 to a port 48 in a previously known mechanical operating unit 58. This is of any desired construction but may, for example, be comprised of a cylinder having a head 52 secured by a bolt 53 and yoke 54 to a pivot 55 mounted on the U-beam 4 of the chassis and to which it is secured by a bolt 55;- On the bolt 53 there is a baflie 58 on the exterior of the head so as to provide access of air to the ports 58 in said head, which lead into the cylinder 5| having a horsehair packing 88 carried in an enclosure 8| having air openings 52, so as thus to permit the access of air to the cylinder while separating dust therefrom. In the cylinder 5| there is a piston 53 having a rubber seal 84, said piston 53 being connected by a piston rod 85 to a brake rod 65 by means of a screw-threaded connecting member 81. Around the piston rod there are the usual bushing 88, rubber seal 58 and rubberboot 18, the ends of which are connected, respectively, to the cylinder 5| and the connecting member 81. This construction is also described in my copending application upon Apparatus for controlling -the application of power, Ser. No..241,312, filed November 19, 1938. The brake-operating-rod l3 leads to the upper end of a lever 1| having a pivot 12 and the lower end is connected by a slotted member 18 to the rod 85. The pivot 12 is comprised of a shaft." on which the lever 1| is tightly secuied, which extends into a Loughead master cylinder 15, which is an apparatus designed for converting mechanical movement into hydraulic pressure, the details of which form no part of the present invention, and which are utilized as disclosed in the Loughead et al. Patent No 1,707,063, granted March 26, 1929. The hydraulic pressure produced by the Loughead master cylinder 15 is conveyed by a pipe 15 to a pair of front wheel brakes through branch pipes 11 and 18 for the actuation of the front wheel brakes in the usual way. As will be noted, the booster 58 may add additional power to the manual power applied to the lever 1| by means of the rod 88.

The modulated pressure delivered by the pipe 48 is also arranged to be conveyed by a pipe 18 to a relay valve 88 through a port 8|. The said relay valve 88 is comprised of a casing 82 to the forward end of which there is screw-threaded a shell 83, by means of a coupling member 83a, having a screw-threaded closure 84 arranged to receive a manual actuating rod 85 connected to a head 86 in a sliding sleeve 81 having a venting port 88 adapted to pass over a venting port 88 in the shell 83, these ports 88 and 88 being merely breather openings. The sliding sleeve 81 has at its rear end a vented closure 88 for receiving a valve actuating rod 8| around which there is a spring 82 held on the rod 8| by a retainer washer 83 and a nut 84. The said rod 85 is connected by a yoke 85 and a pin 88 to a spring 81 which in turn is connected by a clamping member 88 to an emergency brake operating rod 88 connected to a hand lever |8l having a pivot |8| at any desired point on the automobile chassis.

I he rear end of the rod 8| has an enlargement I82 which cooperates with a transverse forward stop I83 in the sleeve 81 and provides an abutment for receiving at the rear thereof a valveoperating, plunger |84 tightly mounted on a reduced portion |88 of the rod 8| having a rubber seal M5 at its forward end. The inlet for the modulated pressure 8| is in the chamber, which is in the rear of the plunger I84, so as to move the plunger M4 in opposition to the high pressure hydraulic liquid conveyed to the other side of the plunger I84 by a passageway I88 which communicates with a high pressure liquid inlet I81 on the valve casing 82. The rear end of the chamber formed by the plunger N4 is closed by a rubber-sealed partition "8 through which -flie reduced portion |88 at the rear end of the rod 8| passes. so as to abut against a valve member 8 reciprocable within an annular member I having ports 2 communicating with an annular passageway ||8 communicating with a'low pressure or return inlet H4. The said valve member III has a flat face 5 which is adapted to seat against a valve seat 8 on a tubular valve member 1 which is constructedthe same as the tubular valve member 3| previously described. This tubular valve member has a tapered valve element |8 which cooperates with a valve seat 8, the same as in the case of the valve 3| previousiy'described. This valve, through transverse ports I28, gives access for the high pressure liquid to the interior of the tubular valve 1 from an annular passageway |2|,ports I22, a passageway I28 and the high pressure liquid inlet I81. The high pressure liquid supplied to the port N1 is received from a pipe I24 and the said high pressure liquid is received by the inlet 34 from a pipe I25 havng a flexible rubber connection I25a, both of which pipes lead to a high pressure supply reservoir I26 supplied from a rotary pump I21 driven by an electric motor I28, pressure within the pressure chamber I21 being maintained substantially uniform by means of an accumulator I29 having a series of coil springs acting on a plunger at one end of the high pressure chamber I26. The details of the structure of the accumulator I29, reservoir I26, pump I21 and electric motor I28 do not constitute part of the invention of the present application but are shown in detail in my copending application upon Pressure accumulator apparatus, Ser No. 105,679, filed October 15, 1936, now Patent No. 2,197,772, April 23, 1940, as well as my application upon Electroflow power supply systems, Ser. No. 28,699, filed June 2'1, 1935, Patent No. 2,136,638, granted November 15, 1938. The low pressure of exhaust liquid discharged by the port H4 is conveyed by a pipe I3I .to the low pressure side of the accumulator I29 and the same is true with regard to the low pressure liquid discharged from the port 35 which is conveyed by a pipe I32 having a flexible rubber connection I32a also to said low pressure side of the accumulator I29. The low pressure side of said accumulator is furthermore connected to a filler pipe I33 which leads to a filler reservoir I34 having a pipe I35 connected by a filler pipe I36 to the top of the Loughead master cylinder 15 and by a pipe I31 connected in turn to the low pressure pipe I3I.

The high pressure liquid normally keeps the valve I I5, II6 closed and the valve II8, I I9 open so that the high pressure liquid passes around the valve II8,'II9 through the ports I29 and thence through the interior of the tubular valve I I1 and out through a coupling member I38 and a pipe I39 to a port I40 on an automatic pack device I provided as a safety feature and which automatically applies the brakes on the failure of the liquid pressure. This automatic pack I is comprised of a hydraulic pressure chamber I42 in which the pressure liquid operates on the forward face of a piston I43 and in opposition to a series of springs I44 which normally press the piston I43 forwardly to apply the brakes. The said piston I43 has a cylindrical reduced extension I45 which is connected by a screw I46 to a slidable spring-retaining plate I41 on which the springs I44 are supported at one end thereof. Guide tubes I48 pass through the springs I44 and through the plate I41, said tubes being held in place by rods I49 passing through said tubes and screw-threaded at one end in the casing of the chamber I42. At this end centering members I58 on said rods keep the tubes I48 in place and at the rear end centering plates II on said rods also act as abutments for the springs I44. The rods I49 at this end pass through a' head I52 which, by means of nuts I53 on the rods I49, hold an enclosing shell I54 in place. On the forward face of the said piston I43 there is a piston rod I55 which extends through a packing I56 against a plunger contained in another Loughead master cylinder I51 and constructed the same as in the Loughead patent above referred to and as shown in the said Loughead patent, except that in this instance, instead of a lever actuation of the Loughead cylinder the end of the piston rod I55 abuts against a plunger I58 in the said Loughead cylinder, the same as the usual plunger contained in the master cylinder 15 above referred to and in the said Loughead patent. The hydraulic liquid for the control of the rear brakes passes out of the Loughead master cylinder I51 through a port I59 and thence by branch pipes I60 and I6I to the operating parts of the rear wheel brakes in the'usual way. In case of emergency, should it be desired to release the brakes when they are on, due to the pressure received from the Loughead master cylinder to the pipe I59,-there may be provided for such emergency a by-p ss pipe I62 leading from the pipe I59 to the interior of the Loughead master cylinder I51, that is to say to a point outside of the plunger I58. This by-pass pipe I62 can be provided with an operating valve I63 adapted to be opened by a bell-crank lever I64 and a Bowden wire I65 leading to a manually operable pullknob I66 on the dash I61 of the automobile.

In Figs. 8 and 9 I have shown a modified form of the relay valve structure which, however, operates in substantially the same manner as the relay valve structure shown in Fig. 5, although the valve parts in this instance are somewhat simpler in construction. In the form of my invention shown in Figs. 8 and 9 there is a relay valve housing I 69 having holes I10 and HI thereon for attachment of the housing to any desired part of the chassis of the automobile. At its forward end there is a screw-threaded cap I12 closing a longitudinal bore I13 within the housing in which the valve'parts are carried. Said housing, furthermore, at this end, carries three ports I14, I15 and I16 which are provided for connection, respectively, to the pipes I24, I3I and I39. Within the bore I13 there is located a three-piece cylindrical shell I11 having component parts I11a, I11!) and "10 provided with gaskets I18, I19 and I80, the construction of these parts of the shell and gaskets being the same as in the form of my invention shown in Fig. 3, except in this instance the parts 26a and 26b are combined to form the part of the shell I11a. Within the composite shell I11 there is a tubular valve I8I which is constructed the same as the tubular valve 3| previously described except that in this instance the holes 43 are omitted and four flat areas I82 are located near the end of the valve shown at the right of the tubular valve in Fig. 8. Also, in this instance, within the tubular valve I8I there is a spring I83 of small diameter and a large spring I84 which springs are arranged and operate like the springs 21 and 24 previously described. The smaller spring I83 normally keeps open a flat valve member I85 cooperating with the-adjacent end of the tubular valve I8I to keep the valve member I85 normally awayfrom its seat I86 on this end of the-tubular valve, constructed the same as the valve seat 32 previously described. Intermediate its ends the tubular valve I8I has an annular tapered valve member I81 constructed the sameas the valve member 4I previously described and which cooperates with a valve seat I88 arranged the same as the valve seat 48 previously described. The forward end of the tubular valve I8I leads to the high pressure port I14, the intermediate valve I81, I88 controls communication with the low pressure port I15, and the valve I85, I86 controls communication between the interior of the tubular valve I8I and the modulated pressure port I16; The position of the valveelement I85 is controlled by a plunger I89 passing through an end closure I99 screwthreaded in the housing I69, the said closure I98 acting as a coupling-for connecting the housing I" with a cylinder IQI to which it is screwthreaded, said cylinder having a piston I82 therein to which the plunger I8! is connected. A vent I" is provided in the cylinder Ill at the forward end of the piston I82. At the rear end of the piston I82 there is a U-shaped rubber sealing member I94 to seal a chamber "5, which has a bleeder opening I" closed by a screw-plug I81 which can be removed when desired to permit the escape of accumulated'air from the chamber Ill. The said chamber I" is connected by a screw coupling I98 to the pipe 1|.

In the operation of the apparatus, referring first to the embodiment of my invention shown in Figs. 1 to 7,, the system having been supplied with the required hydraulic brake fluid through the filler tank I34, the apparatus is ready for the operation of the brakes in the control of the automobile. It will be noted that the hydraulic brake fluid, which is of any desired character, is supplied by the filler tank I34 to the Loughead booster I as well as the Loughead brake-operating-element I51 which is connected to the automatic pack I and also the low pressure reservoir accumulator I29, and the said tank I34 receives the returned low pressure liquid through the pipe Hi from the control or relay valve II as well as from the low pressure outlet 35 on the main modulating valve. When the brakes are to be operated, the pedal-lever 5 is moved downwardly to the extent desired and thereby the desired amounts of a modulated high pressure liquid are allowed to pass by the valve 4|. 4| and thus applied by the pipe 4| to operate the brakes, and which is coordinated in extent to the amount or the degree of the pressures exerted manually on the pedal-lever 5. When this takes place the liquid received by the accumulator I28 placed under high pressure by the pump I21, is delivered by the pipe I25 therefrom and the outlet valve 25, 32 having been closed and the high pressure inlet valve 40, 4I having been opened manually, the said liquid passes from the port 34 through openings 3|, openings 4| and passageway 44 to the chamber 45 where the pressure on the end of the tubular valve 3i will close the valve 4|, 4| unless further liquid is being admitted. In this way, although power derived from the high pressures is applied tothe brakes, the amount of the same is determined by the feel which reacts on the foot through the pedal lever 5. It will be noted, furthermore, that by applying the manual pressure to the pedal-lever 5 the front brakes are applied manually in any event due to the mounting of the valve casing II on the brake-rod I3 and which applies hydraulic pressure from the Loughead master cylinder I! to the front brakes II. This effect is, however, boosted by reason of the modulated pressure delivered through the pipe 4| to the hydraulic booster SI and thence to the lever 'II on the Loughead mas- I ter cylinder Ii. This modulated pressure derived from the pipe 4| is furthermore conveyed by the pipe 39 to the control or relay valve The latter is, in one form of actuation, connected to the emergency brake hand-lever III in that thereby a pull on the rod |l through the interposed spring 92 will result in the piston "4 moving to the left to open the valve I I5, I I| which is normally shut, due to the relatively large size of the piston "4, by the high pressure liquid from the passageway I|| moving the piston I to the right and which valve H5, H4 communicates with the low pressure outlet II4 so as to close the normally-open high pressure inlet valve H8, H9, thus permitting to the extent desired the modulated escap through the pipes 1| and 4| from the modulating valve 4|, 4| and supply of liquid to the chamber can similarly act on the right face of the piston I04 to bring about the modulated pressure control and operation of the said automatic pack "I and the rear brakes I" connected thereto. In this operation, the change by increments or decrements of the pressures established hydraulically on the right face of the piston "4 controls the opening of the outlet valve Hi, i and closing of the inlet ,valve II|, II|. When the valve H8, H9 is closed and the valve H5, H6 opened the liquid passes out from the pipe I" through the valve H5, 4 to the pipe III and back to the accumulator. When the brakes are being applied at a given degree both of the valves H5, H6 and II|, II! are closed as the decrease of the pressure in the pipe I34 permitted by the particular pressure on the right face of the piston I04 will continue until the lessened pressure on the face of the valve member I" causes the pressure on the left face of the piston III to move the valve member Ill into closed position. In other words, the tubular valve member III operates similarly to the valve member 3| but in the reverse order. It will be noted, however, that either of these types of actuation of the control or relay valve 8| results in a reverse modulation, that is to say in pressure conditions within the pipe I39, which are inversely proportioned or related to the modulated pressure in the pipe I9.

' In other words, as the pressure admitted through the pipe I! increases, the pressure within the pipe I39 decreases and the pressure in the pipes lil, Iil increases. This enables a safety control or operation of the rear brakes to be attained by reason of the fact that the springs I44 normally press the rear brakes into action through the agency of the Loughead master cylinder in which conveys the resultant hydraulic pressure thereto through the pipe III and, when there is no manual actuation from the emergency lever I nor from the application of modulated high pressure through the pipe 1|, the high pressure liquid which is supplied from the pipe I24 normally acts on the front end of the piston I" to keep the valve Ili, II| closed and the valve II|, H9 open, admitting the maximum high pressure through the pipe 3| to the interior of the cylinder I42 50 as to force the springs I44 in a direction keeping the rear brakes in oil-position. The rear brakes are thus applied to the extent desired by releasing the high pressure in the pipe I" to the extent desired from the pipe I" so that the released liquid passes out through the low pressure outlet pipe I|I back into the filler system. In other words, if there is a breakage or failure of the hydraulic system the rear brakes are automatically thrown into action so as to apply the brakes. If this should occur the rear brakes can be thrown off manually, if desired, by the actuation of the bell-crank lever I44 from the handle ii! on the dash, the eifect of which is to release the hydraulic brake fluid from the pipe I" so as to allow it to enter the reservoir which forms a part of the Loughead master cylinder I". q

The modification of my invention shown in Figs. 8 and 9 is a modification of the control or relay valve 88. The operation of this modified form ,of control or relay valve is substantially the same as in the operation of the control or relay valve 80 except that in this instance, for simplicity, there is shown no emergency brake manual control connected thereto. A further difierence in this instance is that the valve I85, I86 is normally open while the valve I81, I88 is normally closed. Consequently, in this instance the high pressure brake fluid which normally keeps the rear brakes I68, iii in ofl-position is received through the pipe I88 leading to the auto matic pack from the high pressure pipe I24 and the interior of the valve I 8|. Upon actuation of the valve I8I by the modulated high pressure liquid received from the pipe 19 the valve I85, I88 is closed and the valve I81, I88 is opened so that the amount of the high pressure brake fluid desired to be released is carried away through the low pressure exhaust pipe I3I.

It will be understood that in all of these modulator valve constructions I1, 88 and I68 the modulating effect described in the previously described operation herein takes place, except that in the valves 80 and I89 there is an inverse modulating eflect obtained. These actions of the three valves so as to obtain a modulated effect by the admission or release of small increments of the brake fluid to the extent desired, in order to obtain the desired degree of high pressure in the on-modulation, can take place likewise and with the same effectiveness in the off-modulation and in an entirely comparable and similar manner. In this way, in the on-modulation the increasing increments of modulating fluid obtain increasing brake pressures in accordance with the amount of manual pressure applied but at very much higher pressures than the manual pressure itself. and in the off-modulation by decreasing pressures applied as desired manually, corresponding but very much higher decreasing pressures are obtained on the brakes at will until they are finally entirely released. At all times, however, the reaction on the foot, through the lever II and pedal 5, of the amount of high pressure liquid manually admitted produces from the chamber 45 on the head 25 a feel, that is to say an amount of reaction pressure coordinate to the extent to which the brakes are being applied. This amount of high pressure liquid applied 'to actuate the brakes can be changed manually by increments in. the on or of! modulation, as desired, to change the braking eflect, but while the brakes are on after each admission or discharge of an amount of the high pressure liquid, the valves 25, 82 and III, ll remain closed until a further change in the amount of high pressure liquid present is made manually by the pedal 5.

While I have described my invention above in detail I wish it to be understood that many changes may be made therein without departing from the spirit of the same.

I claim:

1. In an apparatus of the character described, a work-performing element, means for applying a varying degree of fluid pressure, said means being reactive to the pressures applied thereby, and a valve apparatus constructed to receive the same and deliver therefrom to the work-performing element a fluid pressure which decreases coordinately as the fluid pressure received increases.

2. In an apparatus of the character described, means for applying a varying degree of fluid receive the same and deliver therefrom a fluid pressure which decreases as the fluid pressure received increases, said valve apparatus comprising a tubular valve having an end valve seat, a movable valve element. contacting with said end valve seat, a, tapered valve element on the tubular valve, and a valve seat cooperating with the tapered valve element.

3. In an apparatus of the character described, means for applying a varying degree of fluid pressure, a valve apparatus constructed to receive the same and deliver therefrom a fluid pressure which decreases as the fluid pressure received increases,- and an automotive accessory connected to the delivery outlet of the valve apparatus for the actuation of said accessory, said valve apparatus comprising a tubular valve having an end valve seat, a movable valve element contacting with said end valve seat, a tapered valve element on the tubular valve, and a valve seat cooperating with the tapered valve element.

4. In an apparatus of the character described. means for applying a varying degree of fluid pressure, and a valve apparatus constructed to receive the same and deliver therefrom a fluid pressure which decreases as the fluid pressure received increases, said valve apparatus comprising a tubular valve constructed to receive the delivery fluid pressure at one end and having an end valve seat at the other end, a movable valve element contacting with said end valve seat, a tapered valve element on the tubular valve, and a valve seat cooperating with the tapered valve element, said tapered valve and seat being constructed to control the delivery from the valve structure.

5. In an apparatus of the character described,

means for applying a varying degree of fluid pressure, a valve apparatus constructed to receive the same and deliver therefrom a fluid pressure which decreases as the fluid pressure received increases, and an automotive accessory connected to the delivery outlet of the valve apparatus for the actuation of said accessory, said valve apparatus comprising a tubular valve constructed to receive the delivery fluid pressure at one end pressure, and a valve apparatus constructed to and having an end valve seat at the other end, a movable valve element contacting with said end valve seat, a tapered valve element on the tubular valve, and a valve seat cooperating with the tapered valve element, said tapered valve and seat being constructed to control the delivery from the valve structure.

6. In an apparatus of the character described, means for applying a varying degree of fluid pressure, and a valve apparatus constructed to receive the same and deliver therefrom a fluid pressure which decreases as .the fluid pressure received increases, said valve apparatus comprising a tubular valve constructed to receive the delivery fluid pressure at one end and having an end valve seat at the other end, a movable valve element contacting with said end valve seat,

a tapered valve element on the tubular valve,

and a valve seat cooperating with the tapered valve element, said end valve and movable valve element being constructed to control the delivery from the valve structure.

7. In an apparatus of the character described, means for applying a varying degree of fluid pressure, a valve apparatus constructed to receive the same and deliver therefrom a fluid pressure which decreases as the fluid pressure received increases, and an automotive accessory connected to the delivery outlet of the valve apparatus for the actuation of said accessory, said valve apparatus comprising a tubular valve constructed to receive the delivery fluid pressure at one endand having an end valve seat at the other end, a movable valve element contacting with said end valve seat, a tapered valve element on the tubular valve, and a valve seat cooperating with the tapered valve element, said end valve and movable valve element being constructed to control the delivery from the valve structure.

8. In an apparatus of the character described, means for applying a varying degree oi fluid pressure, a valve apparatus adapted to receive the same and deliver therefrom a fluid pressure which decreases as the fluid pressure received increases, an automotive accessory connected to the delivery outlet of the valve apparatus for the actuation oi said accessory, and a spring-operating means adapted to press the accessory into action, having a connection to said delivery for moving said spring so as to throw the accessory out of action.

9. In an apparatus of the character described, means for applying a varying degree of fluid pressure, a valve apparatus adapted to receive the same and deliver therefrom a fluid pressure which decreases as the fluid pressure received increases. an automotive accessory connected to the delivery outlet of the valve apparatus for the actuation of said accessory, said valve apparatus comprising a tubular valve having an end valve seat, a movable valve element contacting with said end valve seat, a tapered valve element on the tubular valve and a valve seat cooperating with the tapered valve element, and a spring-operating means adapted to press the accessory into action, having a connection to said delivery for moving said spring so as to throw the accessory out of action.

10. In an apparatus of the character describedv means for applying a varying degree of fluid pressure, a valve apparatus adapted to receive the same and deliver therefrom a fluid pressure which decreases as the fluid pressure received increases, an automotive accessory connected to the delivery outlet oi the valve apparatus for the actuation oi. said accessory, said valve apparatus comprising a tubular valve having an end valve seat, a movable valve element contacting with said end valve seat, a tapered valve element on the tubular valve and a valve seat cooperating with the tapered valve element, said tapered valve and seat being adapted to control the delivery from the valve structure, and a spring-operating means adapted to press the accessory into action, having a connection to said delivery for moving said spring so as to throw the accessory out of action.

11. In an apparatus of the character described, means for applying a varying degree of fluid pressure, a valve apparatus adapted to receive the same and deliver therefrom a fluid pressure which decreases as the fluid pressure received increases, an automotive accessory connected to the delivery outlet of the valve apparatus for the actuation of said accessory, said valve apparatus comprising a tubular valve having an end valve seat. a movable valve element contacting with said end valve seat, a tapered valve element on the tubular valve and a valve seat cooperating with the tapered valve element, said end valve and movable valve element being adapted to control the delivery from the valve structure, and a spring-operating means adapted to press the accessory into action, having a connection to said delivery for moving said spring so as to throw the accessory out oi action.

12. In an apparatus of the character described. means for applying a varying degree of fluid pressure, said means being reactive to the pressures applied thereby and a valve apparatus constructed to receive the same and deliver therefrom a fluid pressure which decreases as the fluid pressure received increases, said valve apparatus comprising a valve controlling the said delivery and a movable means constructed to normally keep said delivery valve open but constructed to time said valve under the influence of the fluid received.

13. In an apparatus of the character described, means for applying a varying degree of fluid pressure, said means being reactive to the pressures applied thereby and a valve apparatus constructed to receive the same and deliver therefrom a fluid pressure which decreases as the fluid pressure received increases, said valve apparatus comprising a valve controlling the said delivery,

a movable means constructed to normall; keep said delivery valve open but constructed to close said valve under the influence of the fluid received, and an exhaust valve constructed to be brought into communication with said delivery under the influence of the fluid received.

14. In an apparatus of the character described, means for applying a varying degree of fluid pressure, and a valve apparatus constructed to receive the same and deliver therefrom a fluid pressure which decreases as the fluid pressure received increases, said valve apparatus comprising a valve controlling the said delivery, a movable means constructed to normally keep said delivery valve open but constructed to close said valve under the influence of the fluid received, and a manually operable device constructed to operate said movable means.

15. In an apparatus of the character described, means for applying a varying degree of fluid pressure, and a valve apparatus constructed to receive the same and deliver therefrom a fluid pressure which decreases as the fluid pressure received increases, said valve apparatus comprising a valve controlling the said delivery, a

movable means constructed to normally keep said exhaust valve adapted to be brought into communication with said delivery under the influence oi the fluid received, and a manually operable device constructed to operate said movable means.

16. In an apparatus oi! the character described, means for applying a varying degree 01 fluid pressure, said means being reactive to the pressures applied thereby and a valve apparatus constructed to receive the same and deliver therefrom a fluid pressure which decreases as the fluid pressure received increases, said valve apparatus comprising a valve controlling the said delivery, and a plunger constructed to normally keep said delivery valve open but constructed to close said valve under the influence of the fluid received.

17. In an apparatus of the character described, means for applying a varying degree of fluid pressure, said means being reactive to the pressures applied thereby and a valve apparatus constructed to receive the same and deliver therefrom a fluid pressure which decreases as the fluid press re received increases, said valve apparatus comprising a valve controlling the said delivery, a plunger constructed to normally keep said delivery valve open but constructed to close said valve upon the influence of the fluid re- -ceived, and an exhaust valveadapted to be brought into communication with said delivery under the influence of the fluid received.

18. In an apparatus of the character described,

:meansfor applying a varying degree of fluid pressure, said means being reactive to the pressures applied thereby and a valve apparatus constructed to receive the same and deliver therefrom a fluid pressure which decreases as the fluid pressure received increases, said valve apparatus comprising a valve controlling the said delivery, and a plunger constructed to normally keep said delivery valve open but constructed to close said valve under the influence of the fluid received, one face of said plunger being located so as to receive the force of the incoming fluid and the other face of said plunger being in communication with a source of high pressure fluid, the admission of which to said delivery is controlled by the delivery valve.

19. In an apparatus of the character described, means for applying a varying degree of fluid pressure, said means being reactive to the pressures applied thereby and a valve apparatus constructed to receive the same and deliver therefrom a fluid pressure which decreases as the fluid pressure received increases, said valve apparatus comprising a valve controlling the said delivery, a plunger constructed to normally keep said delivery valve open but constructed to close said valve upon the influence of the fluid received, and an exhaust valve adapted to be brought into communication with said delivery under the influence of the fluid received, one face of said plunger being located so as to receive the force of the incoming fluid and the sure fluid received, said tubular valve having a lateral port for conveying the high pressure fluid to the interior of the valve.

22. In an apparatus of the character described, means for applying a'varying degree of fluid pressure, and a valve apparatus adapted to receive the same and deliver therefrom a fluid pressure which decreases as the fluid pressure received increases, said valve structure comprising a tubular reciprocable valve having thereon a delivery control valve member, a source of high pressure fluid, access of which to said delivery is controlled by said delivery valve, a discharge valve member adapted to cooperate with the tubular valve to act as a discharge for the delivered fluid when the delivery valve is closed, and means to alternately seat and unseat the said two valves under the influence of the pressure fluid received, said tubular valve having a flattened lateral area for establishing communication between the delivery and the discharge valves.

23. In a hydraulic power system, an automotive accessory, a manual actuator therefor, a

other face of said plunger being in communication with a source of high pressure fluid, the admission of which to said delivery is controlled by the delivery valve,

20. In an apparatus of the character described, means for applying a varying degree of fluid pressure, and a valve apparatus adapted to receive the same and deliver therefrom a fluid pressure which decreases as the fluid pressure received increases, said valve structure comprising a tubular reciprocable valve having thereon a delivery control valve member, a source of high pressure fluid, access of which to said delivery is controlled by said delivery valve, a discharge valve member adapted to cooperate with the tubular valve to act as a discharge for the delivered fluid when the delivery valve is closed, and means to alternately seat and unseat the said two valves under the influence of the pressure fluid received.

21. In an apparatus of the character described, means for applying a varying degree of fluid pressure, and a valve apparatus adapted to receive the same and deliver therefrom a fluid pressure which decreases as the fluid pressure received increases, said valve structure comprising a tubular reciproable valve having thereon a delivery control valve member, a source of high pressure fluid, access of which to said delivery is controlled by said delivery valve, a discharge valve member adapted to cooperate with the tubular valve to act as a discharge for the delivered fluid when the delivery valve is closed, and means to alternately seat and unseat the said two valves under the influence of the presmodulating valve connected to said manual actuator for supplying modulated high pressure, a control valve adapted to receive the modulated pressure, a source of high pressure fluid connected to the modulating valve and the control valve, an actuating means for actuating the accessory, a high pressure connection from said control valve for controlling the accessory, a reservoir for supplying the source of high pressure fluid and low pressure connections from said modulating valve and said control valve to said reservoir.

24. In a hydraulic power system, an automotive accessory, a manual actuator therefor, a modulating valve connected to said manual actuator for supplying modulated high pressure, a control valve adapted to receive the modulated pressure, a source of high pressure fluid connected to the modulating valve and the control valve, an actuating means for actuating the accessory, a high pressure connection from said control valve for controlling the accessory, a reservoir for supplying the source of high pressure fluid, low pressure connections from said modulating valve and said control valve to said reservoir, and a flller tank connected to said low pressure connections.

25. In a hydraulic power system, an automotive accessory, a manual actuator therefor, a modulating valve connected to said manual actuator for supplying modulated high pressure, a control valve adapted to receive the modulated pressure, a source of high pressure fluid connected to the modulating valve and the control valve, a spring actuating means for actuating the accessory, a high pressure connection from said control valve for throwing the accessory out of action by the movement of said spring, hydraulic means connecting said spring with said accessory,

. a reservoir for supplying the source of high pressure fluid, low pressure connections from said modulating valve and said control valve to said to press the accessory into action, having a connection to said delivery for moving said resilient means so as to throw the accessory out or action.

27. In an apparatus of the character described, adapted to accumulate a fluid pressure diflering from the atmospheric pressure, a work-performing element, means for applyi g a "47 degree of hydraulic pressure, said means being reactive to the pressures applied thereby, and a valve apparatus constructed to receive the same and apply to the work-performing element accumulated fluid pressure which relaxes as the hydraulic pressure received increases.

28. In an apparatus of the character described, adapted to accumulate a fluid pressure diilering from the atmospheric pressure, a work-performing element, manual means including a hydraulically operated plunger for applying from the plunger a varying degree of hydraulic pressure, a

said means being reactive to the pressures applied thereby, and a valve apparatus constructed 

